高硅铝合金的电脉冲孕育处理与液-固相关性

Thermodynamic analysis of liquid-solid state correlation of silumin under electric pulse

以液态合金的多相结构模型为基础,对电脉冲作用下高硅铝合金熔体结构变化进行了热力学分析,并研究了电脉冲作用下Al-22%Si合金凝固组织的显微硬度以及凝固相变点的变化.实验结果表明,电脉冲促进了呈"胶体"状态存在的Si粒子在Al-22%Si合金熔体中的分解,提高了熔体的均匀程度,部分消除了来自Si原料的遗传性;电脉冲孕育处理提高了Al-22%Si合金熔体的过冷能力,增加了Si粒子在基体组织中的过饱和度,提高了基体的显微硬度;Al-22%Si合金基体显微硬度值的变化显示熔体对于电脉冲频率的响应比较敏感.

Based on the micro-multi-phase structure model of molten alloys, the thermodynamics of the Al-Si molten alloy structure under electric pulse was analyzed, and the changes in matrix micro-hardness and solidifying point of the Al-22% Si alloy under electric pulse were studied. It is shown that electric pulse promotes the decomposition of Si particles in colloidal state in the alloy melt, improves the homogeneous degree of the melt, and eliminates the heredity from raw material partially. Electric pulse modification increases the super cooling degree of the Al-22 % Si alloy melt and enhances the supersaturated degree of Si particles in the matrix, thereby increases the micro-hardness of the matrix. The variation in micro-hardness of the alloy matrix indicates that the alloy melt structure was sensitive to the change in electric pulse frequency.